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Old 07-23-2001, 04:03 PM
Ishmeal Ishmeal is offline
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Join Date: Jun 2001
Posts: 31
Welcome to Weather101...
I like to compare the information on www.intellicast.com and www.accuweather.com...My military aviation carreer has given me a fairly good weather background but it's a "probability" game with "educated" guesses mixed in with a basic weather foundation...
Intellicast has very good "radar loops" that show weather movement over a six hour period and has good visuals on fronts and areas of concern...the "surface maps" show a graphic representation of "High" pressure and "Low" pressure areas and the white "isobar" gradient lines tell alot about wind speed and direction ande the overall strength of the pressure system. Check out hurricane isobars and you get the picture.
I'll start off with the "radar loop" to get the big picture, trend and frontal information...then I will go to the surface maps to locate "low" pressure areas (counter clockwise flow) and "high" pressure areas (clockwise flow)...(south of the equator "lows" are clockwise and "highs" are counter clockwise...I shall only consider the northern hemisphere for this discussion)...There WILL be a test soonerorlater!

If the isobar lines (the white lines that circle the high/low pressure areas) are widely spaced the pressure gradient is weak and the winds will be light...tightly spaced isobar lines would indicate a stronger pressure gradient and will produce stronger winds.
As far as the beach weather is concerned...weak pressure gradient lines will produce little or no winds...as the cool morning passes and the sun heats up the land mass, air over the land mass heats and, since warm air rises, the "void" created by this rising warm air must be filled/replaced with more air and what you have is a "shore breeze" that starts when the land mass heats up and deminishes as the sun heads low in the west which cools the land mass and the shore breeze dies off...
If the isobars are tightly spaced the resulting winds will "overpower" the shore breeze and there will be a prevailing breeze/wind driven by the location of the center of the "high" or "low" pressure areas...these winds will parallel the isobar lines seen on the surface maps.
Closely spaced isobar lines=very windy
Widely spaced isobar lines=slightly windy
Very weak pressure areas with widely spaced isobar lines will inspire the mid-morning shore breeze (caused by land mass warming and hot air rising being replaced by the cooler air from off shore) that dies off as the sun goes down.
If it's windy in the morning the wind will be "driven" by the pressure gradient isobars which will overpower the land mass warming mechanics...and the wind will continue until the pressure system moves on and pressure eases thus spreading out the isobar lines on the surface map...wind calm!
Weather reports play the odds with educated guesses and tend to be "conservative"...S_ _ T happens!?

BLAH BLAH BLAH...I'm getting carried away and will quietly sit back down and field any question (remember, I'm a pilot, not a weather person...)
Thank you for your time and attention...you can take back the soap box!
LET'S GO FISHING!
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